The present invention relates to a bag house for filtering dust and other particles from a gaseous exhaust from, for example, a combustion system. Specifically, the present invention is related to control and monitoring systems for a bag house.
Bag houses filter dust and other gas borne particles from exhaust gas, such as flue gases from combustion systems. A bag house typically has an array of filter bags. The bag house ducts exhaust through the filter bags. As gas passes through the filter bags, dust and other particles are captured on the surfaces of the media of the filter bags. The buildup of dust and particles on the filter bags continues as the bag house filters dust from the exhaust air.
The buildup of dust and particles on the filter bags eventually clogs the porous media of the filter bags and obstructs the flow of exhaust gas through the bag house. Mechanisms are employed to remove the buildup from bag filter, such as agitators that shake the bags to cause the dust and particles to fall off the bags. In addition or as an alternative to, the bag filters may be cleaned by pulse jets that pulse air jets to the interior of the bag to apply an impulse to the bag that knocks off the dust and particles. However, these mechanisms do not entirely open the porous openings in the media of the bag filters. Even with periodic cleaning operations, the bag filters become clogged and unsuitable after prolonged use in a bag house.
Bag filters are conventionally assigned an operational life by the manufacturer of the bag. The operator of the bag house replaces the filter bags before they reach the end of their operational life. The assigned operational life of a bag filter is conventionally a fixed period. The assigned operational life may be assigned by bag filter manufacturer and is based, in part, on the type of bag house into which the filter is to be used.
The assigned operational life is based on assumptions of the operating conditions in the bag house. The operating conditions in a bag house may vary depending on ambient conditions, the composition of the mixture of exhaust gas, dust and other particles passing through the bag house and other factors. These variations in operating conditions affect the actual operational life of the bag filters. The assigned operational life does not vary and thus does not account for variations in the actual operation life of a bag filter. At the expiration of the assigned operational life, the bag filter is typically replaced regardless of whether there is remaining actual operating life of the filter. Bag filters having an expired actual operating life may remain in use in a bag house because the assigned operational life of the filter. Similarly, bag filters having an expired actual operating life may remain in use in a bag house because the assigned operational life of the filter has not expired.